I bought my machine new from Probotix in April of 2013.I think it is a MK1 controller (green board with blue screw headers that has probotix screen printed on it) but I'm not sure, I had the same issues when I first bought the machine but ended up storing it till recently.

Any way I'm having issues with a "buffer error" box stopping my machine, and I am looking for away prevent this so that I do not have to stay with the machine to complete my programs. My guess is a lower feed rate but I am hopping for another solution.

software is up to date, firmware says it is.cutting less then 20 IPM (inchs per minute)new usb cable filtered power on my router motor to help with AC noisewindows 7 64bit 2.9GHz laptop 4gigs ram, with the auto power cut off, turn off for usb ports performance setting set to high

If your g-code (also please send us your g-code program and your settings file) is consisted from large number of small lines, which are represented as instructions for controller you may have buffer problems when using Mk1.

Mk1 buffer has only 14 instruction locations. Communications between PC (CNC USB software) and controller must be flawless in order to machine works fluently. Sometimes computer "assignes" priority to hard disk (light flashes on computer panel) and therefore slows down the CNCUSB controller software, which results as lower rate of instruction sending.

Buffer empties (jerky movement)CNCUSB Controller senses empty buffer and speeds up the rate of instruction sending.PC at one moment resolves priority to hard drive and CNCUSB controller software sends at current high instruction sending rate one instruction too many. Buffer is now full, and software gives error.

Possible solutions:1. Lower speed2. Program without so many short lines3. More powerful controller (Mk3 series....)

Also:All devices that are connected so same root hub need to share bandwidth.Never use any USB 1.0 devices connected to same root hub as controller.

You can download this toolhttp://www.planet-cnc.com/files/usbtreeview.zipIt will show you tree of all devices connected to your root hubs that share bandwidth. You can try to rearrange them and give controller more chance to communicate with high speed.

Hello. I seem to be having buffer issues with my setup. Running the Mk3/4 board. About a minute after I start the g-code my machine stops. I am trying a 3d carve with a tapered endmill (1/16" tip) so yeah producing a lot of short lines. Using V-Carve Pro: 50 inch/min, .06" clearance pass stepover, .01" stepover.